Page 8 - Radiation Safety

RADIATION PROTECTION

Л – mass attenuation coefficient
Incident intensity, I X – material thickness γ, χ - High Z @ High Density materials
Initial intensity I o
- eg : Concrete, Lead, Barium
x
Β - Low Z
Half Value Layer of thickness (HVL) - eg : 10 mm Perspex
X 1/2 = ln 2 Activity Energy
Л n - High Hydrogen content
2
I d = I d 2 Radiation Intensity - Water, Wax, Paraffin
1 1
2 2
I = I e -Лx Depends on Types of
Inverse Square Law o Reduce quantity
Shielding radiation
Distance of RN used
PRINCIPLES Internal Exposure PPE (Gloves, respirator,
Time External Exposure apron, etc.)
Decontamination
D = Dose Rate x Time
RADIATION Hand and body monitoring
PROTECTION

Annual Limit Intake (ALI)
SYSTEMS
INTERNAL
Justification Optimization Dose Limit
Necessity ALARA i. Follows BSS 2010 EXTERNAL
YES (As Low As Reasonably ii. Not include:
NO
Achievable) - Background radiation 1. Occupational Exposure
No exposure - Dose given must be at the - Medical exposure (Radiation Worker)
lowest with most effective - Limit : 20 mSv/y
result 0.4 mSv/week
ii) Supervised Area 0.08 mSv/day
Area which occupational exposure conditions 4. Area 0.01 mSv/hour
are kept under review even though specific 3. Public 2. Student (8 hrs/day; 5 days/week;
protection / protective measures and safety i) Controlled Area Limit : 1 mSv/y 16 years old 50 weeks/year; 2000 hrs/year)
provision are normally needed. -Area which SPECIFIC PROTECTION MEASURES and Lens : 15 mSv/y Limit : 6 mSv/y
SAFETY PROVISIONS are required Skin : 50 mSv/y Lens : 50 mSv/y Lens : 150 mSv/y
iii) Clean Area - To control NORMAL EXPOSURE or preventing the Skin : 150 mSv/y Skin : 500 mSv/y
Area where annual dose received by a worker is spread of CONTAMINATION or preventing/limiting
not likely to exceed the dose limit of public the EXTENT POTENTIAL (3/10 from ADL)